Changing Text Color

How do you change the text color in the area (shown on the linked picture) where it says Sample Text Input, Option Total, Product Price, etc. I am assuming it is CSS related but I can’t seem to find it when searching the HTML code. I use a dark theme and while I can get other text to display properly, these stay blackish and so it can’t be read.

https://ps.w.org/woocommerce-product-addon/assets/screenshot-4.png?rev=2800561